Wastewater fluid level sensing and control system

ABSTRACT

A wastewater fluid level sensing and control system is provided. The system comprises a control panel, a reservoir, at least one pump and a fluid level sensing device. The control panel comprises a housing and user interface input and output devices for use with configuring the operation of the control panel. The control panel may be configured to turn on one or more of the pumps to lower the level of fluid in the reservoir. When the level is above a selectable level, the control panel is operative to cause at least one alarm signal to be output. The control panel may include a touch sensor pad mounted to an inner wall of the housing. Changes in capacitance in the pad as a result of a hand being placed adjacent the sensor on the outside of the housing is operative to cause the control panel to silence the alarm.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. application Ser. No. 10/711,602filed Sep. 28, 2004, which claims benefit of U.S. provisionalapplication Ser. No. 60/507,249 filed Sep. 29, 2003, all of whichapplications are hereby incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to wastewater systems. Specifically thisinvention relates to fluid level sensing and control systems and methodsfor wastewater systems.

BACKGROUND ART

It is often desirable to know information about fluid levels inreservoirs. Determining fluid levels and controlling fluid levels inreservoirs, such as in sewage tanks, wells, water cisterns or tanks, andother fluid system and storage vessels, whether enclosed or open andexposed to the environment, has been done in a number of ways. Forexample, in tanks that are visually accessible, an operator mayperiodically take visual readings of the fluid level.

Visual readings, however, are often not desirable in systems where anautomatic response is required when the fluid level reaches a certainthreshold. In such cases the activation of a pump or valve may benecessary to move more fluid into the tanks or to discharge fluid fromthe tank. In systems where visual readings are not available or when animmediate response is required, control systems are typically employedthat are responsive to a fluid level indication. Such control systemsmay illuminate a light on an indicator panel representing the fluidlevel and/or trip an audible alarm to notify a human operator thatcorrective action is required.

Examples of fluid level sensing devices for use with wastewaterreservoirs or other fluid holding vessels are discussed in U.S. Pat. No.6,595,051 of Jul. 22, 2003 and U.S. Pat. No. 6,443,005 of Sep. 3, 2002which are both incorporated by reference herein.

Different types or configurations of tanks often require different typesor configurations for control systems associated with the tank. Forexample, some tanks may have one pump while other tanks have more thanone pump which are capable of moving fluids out of the tank. Inaddition, some tanks may include fluid level sensing devices in the formof mechanical floats positioned at various levels in the tank, whileother tanks may use fluid level sensing devices such as a pressure belllocated at the bottom of the tank such as shown in U.S. Pat. No.6,595,051.

Although control systems have been produced for each of these systems,such systems are generally limited to working with only a specific typeof wastewater tank configuration. If the requirements for the tankchange over time, a completely new system which can accommodate the newrequirements for the tank must be installed. Thus there exists a needfor a control system which is more easily adaptable to changingrequirements for a wastewater system.

Wastewater control systems are often designed to cause one or more pumpsto start pumping fluid out of a tank responsive to the level of fluid inthe tank. It is often desirable to use pumps with single phase motorsfor this purpose. Because single phase motors do not have multiplephases, to begin rotation, start windings are required to achieve motoracceleration. Historically, this has been achieved with the use of apotential relay that measures the voltage during the start. In responseto the voltage measurement, a relay can be configured to drop out thestart winding. Because start capacitors operate in parallel with thestart winding, the relay must open at the correct time so that thevoltage does not build too high and blow up the start capacitor. Thus,to increase the reliability of such control systems, there exists a needfor a control system which can reliably prevent start capacitors frombeing damaged.

Embodiments of control systems for monitoring and controlling wastewatersystems may include a momentary contact push button accessible from theoutside of the control system housing. Such a push button may be capableof temporarily silencing an alarm produced by the control system untilthe wastewater system is again working properly. For example, thecontrol system may include a circuit board within the housing of thecontrol system which is operative to monitor and control conditionsassociated with a wastewater system. The circuit may include a latchingrelay which is coupled to the push button. The latch relay may beresponsive to the momentary contact push button being pressed to open(i.e., deactivate) the portion of the circuit which produces the alarm.

The momentary contact push button may be positioned on the controlsystem to be accessible by an operator without opening the housing.However, control system housings are often designed to comply with oneor more standards for water resistance such as the National ElectricalManufacturers Association (NEMA) standards. An example of such astandard may included a NEMA 4X standard for a housing which specifiesthat the housing is capable of resisting certain levels of water andcorrosive materials. In a wastewater environment, the control panel maybe relatively close to the fluids that are being monitored andcontrolled by the control panel. In addition, in a wastewaterenvironment, the housing for the control system may be exposed torelatively high levels of water vapor, humidity, or other potentiallycorrosive and destructive gases and fluids. Thus, the circuits withinthe housing of the control system must be protected from the environmentoutside the housing.

Placing holes through the walls of such housings for placement of pushbutton silencing alarms can compromise the NEMA rating of the housing.Although gaskets with oiltight push button switches can be used,adapting a housing to include such a button without compromising theNEMA rating of the housing can add to the complexity and cost of themanufacture of the control system. As a result, there exists a need foran improved housing for wastewater control panels which enables alarmsto be silenced without opening the housing and which is adapted tominimize the opportunity for environmental conditions outside thehousing from degrading the circuits and other components inside thehousing.

DISCLOSURE OF INVENTION

It is an object of an exemplary form of the present invention to providea fluid level sensing and control system.

It is a further object of an exemplary form of the present invention toprovide a fluid level sensing and control system for wastewaterenvironments.

It is a further object of an exemplary form of the present invention toprovide a fluid level sensing and control system which resistspenetration of water and other fluids.

It is a further object of an exemplary form of the present invention toprovide a fluid level sensing and control system which is adaptable tochanging requirements for a wastewater system.

It is a further object of an exemplary form of the present invention toprovide a fluid level sensing and control system which is upgradeable inthe field.

It is a further object of an exemplary form of the present invention toprovide a fluid level sensing and control system which is less expensiveto manufacture relative prior art systems.

It is a further object of an exemplary form of the present invention toprovide a fluid level sensing and control system which is operative toprevent start capacitors for pumps from being damaged.

It is a further object of an exemplary form of the present invention toprovide a fluid level sensing and control system which is capable ofautomatically generating an alarm signal.

It is a further object of an exemplary form of the present invention toprovide a fluid level sensing and control system which is capable ofsilencing the alarm signal in response to an input from an operatorwithout opening a housing for the system.

Further objects of exemplary forms of the present invention will be madeapparent in the following Best Modes for Carrying Out Invention and theappended claims.

The foregoing objects are accomplished in an exemplary embodiment of theinvention with a fluid level sensing and control system which is adaptedto be easily configured and/or upgraded to meet the current and futurerequirements of a wastewater system. An exemplary embodiment may includea housing which comprises therein mounting features for different typesand versions of interface input/output devices, circuit boards, relays,and other types of devices used to measure and control fluids. Thehousing may include a door which provides access to the interior of thehousing. For housings that meet the requirements of one or more NEMAstandards related to water and other chemical resistance, the doorand/or housing may include one or more gaskets, tongue and groovecooperating members, and other sealing features which are operative toprevent fluids such as water from entering the housing.

In an exemplary embodiment, the interior of the housing may include aback panel which is adapted for use to securely mount electricalcomponents such as circuit breakers, contact relays, start capacitors,overload devices, and/or other components used for electricallycontrolling pumps. In the exemplary embodiment, the interior of thehousing may also include a sub-door in hinged connection with thehousing. The sub-door may pivot between an open position and a closedposition. By placing the sub-door in an open position, the componentsmounted to the back panel can be accessed. When the sub-door is in theclosed position, the sub-door may extend between the walls of thehousing with a sufficient size that enables the sub-door to prevent auser's hand from contacting unshielded portions of the electricalcomponents mounted to the back panel.

In an exemplary embodiment, the sub-door may include an inner side andan outer side. When the sub-door is in the closed position, the outerside faces outwardly toward the opening of the housing, while the innerside faces inwardly toward the back panel. In an exemplary embodimentthe inner side of the sub-door is adapted to receive mounted thereto oneor more circuit boards.

The sub-door may further include one or more apertures therethrough. Theapertures may have sizes which enable one or more user interfaceinput/output devices or other components mounted to the sub-door or theback panel to be accessible to a user when the sub-door is in the closedposition. Examples of components which may be accessible include circuitbreaker switches, test/silence alarm buttons, hand run buttons, toggleswitches, digital displays, programming buttons, LEDs, dials, and anyother input or output device which is useful for controlling andmonitoring wastewater systems.

In an exemplary embodiment the back panel may be injection molded withraised mounting elements such as a raised platform for mounting circuitbreakers. The raised platform may have a sufficient height relative theback of the housing to enable the switches of the circuit breakers toextend through an aperture in the sub-door when the sub-door is in theclosed position. The back panel may also include other mountingfeatures, including brackets adapted to mount capacitors to the backpanel.

An exemplary embodiment of the invention includes at least one computerprocessor. In the exemplary embodiment a main processor is included on amain circuit board which is mounted to the inside of the sub-door. Theprocessor and associated circuitry (hereafter referred to as the maincircuit board) is operatively programmed and configured to acquireinformation from components and control the operation of components inthe system. In exemplary embodiments such components may include devicesfor controlling pumps such as power contactors, overload protectiondevices, and start relays. In addition such components may includeinput/output devices such as an alarm flasher, audible relay, audiblesilence relay, seal fail relay, hand/auto operation switch, and runlights. Also, the main circuit board may be operative to provide userinterface input/output devices to enable users to configure the system.

In exemplary embodiments of the system, an optional circuit board may beprovided which includes additional user interface features and otherfunctionality. Such an optional circuit board may include a furtherprocessor, a digital display device, buttons and other user interfacefeatures. In exemplary embodiments the optional circuit board may bemounted to the inner side of the sub-door. The sub-door may includeapertures adapted to provide visibility and/or access to a digitaldisplay and/or buttons respectively of the optional circuit boardtherethrough. In exemplary embodiments the optional circuit board may beprogrammed to provide features such as an elapsed pump operating timemeter, pump off/on cycle counter, liquid level display, time dosingapplications, measurement logs, alarm condition annunciations,telemetry, and communications with remote devices.

In an exemplary embodiment, the processor of the main circuit board isoperative to turn on one or more pumps that are operative to pump fluidsin a wastewater system. For single phase motors, the main board isoperative to activate a start relay that is in operative connection withstart windings of the pump. An overload device may be operative tomeasure the level of current in the AC circuit used to power the runwindings of the motor of the pump. The processor may be operativelyconfigured to monitor the measured current for the pump as the pump isbeing started. When the current falls to a predetermined level, theprocessor is operative to cause the start relays to deactivate the startwindings. In the exemplary embodiment the predetermined level is chosento correspond to the level of current at which the pump should reach adesired level of speed which is less than full operating speed.

Exemplary embodiments of the processor may further be operative tomeasure the amount of time that has elapsed since the start windingswere activated. In addition to deactivating the start windingsresponsive to a current measurement, the processor may furtherdeactivate the start windings after a predetermined amount of time haselapsed since the start windings were activated.

In the exemplary embodiment, the processor may be operative to monitorthe sinusoidal changes in the current of the AC circuit powering the runwindings of the motor of the pump through use of the overload device. Toreduce wear on the contact relay when the pump is started and stopped,the processor may be operative to time the point when the contact relayopens or closes the circuit for the run windings to about correspond tothe cross-over point or zero power point of the sinusoidal change incurrent or voltage in the AC circuit. For example, the processor maycause the contact relay to power the run windings and/or remove powerfrom the run windings responsive to the current or voltage of the ACcircuit being within a predetermined amount of time before or after thecross-over point for the AC circuit. In an exemplary embodiment thepredetermined amount of time may, for example, be about 1 millisecond.

In further exemplary embodiments a device for silencing an alarm may beaccessed from outside the housing which encloses the main circuit boardand other components of the system. Such a device may include a touchsensor pad or plate mounted within the housing. Such a plate may beoperative to experience a change in capacitance in response to a user'shand placed near the plate on the outside of the housing. The processorof the main circuit board may be configured to receive a signalindicative of the change in capacitance of the touch sensor plate and inresponse thereto cause one or more alarms to be silenced.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic view of an exemplary embodiment of a wastewatersystem.

FIG. 2 is a perspective view of an exemplary embodiment of a controlpanel for a wastewater system.

FIG. 3 is a further perspective view of an exemplary embodiment of thecontrol panel.

FIG. 4 is plan view of an outer side of an exemplary embodiment of asub-door of the control panel.

FIG. 5 is a perspective view of an inner side of the sub-door.

FIG. 6 is a perspective view of an exemplary embodiment of a hingebracket.

FIG. 7 is a plan view of the hinge bracket.

FIG. 8 is a perspective view of an exemplary embodiment of a back panelof the control panel.

FIG. 9 shows an exemplary embodiment of a user interface area of thesub-door.

FIG. 10 shows a schematic view of an exemplary configuration ofcomponents operative to silence an alarm.

FIG. 11 shows an exemplary embodiment of a touch sense pad mounted to aninner wall of a housing of the control panel.

FIG. 12 shows a label mounted to an outside wall of the housing.

FIG. 13 shows a schematic view of an exemplary configuration ofcomponents for starting a single phase motor of a pump.

FIG. 14 shows a schematic view of a portion of the circuit on the mainboard which includes selection input devices and contact points forconnecting a voltmeter.

BEST MODES FOR CARRYING OUT INVENTION

Referring now to the drawings, FIG. 1 depicts an example of a wastewatersystem 10 in accordance with an exemplary embodiment. The system mayinclude a fluid-holding vessel or tank 20, a fluid inlet line 30 forbringing fluidized material into tank 20, and a fluid pump 40 fordischarging fluid material from vessel 20 via a discharge line 50. Theexemplary embodiment may further include a fluid level sensing andcontrol system 100. The system may include a control panel 102 with aplurality of different components mounted within a housing 104.

In this described exemplary embodiment, the system 100 includes a fluidlevel sensing device such as a pressure bell 106 and a tubing 48 inoperative connection between the pressure bell 106 and the control panel102. Here, the pressure bell is operative responsive to the pressure ofthe fluid 46 to change the pressure of gases in the tube. The controlpanel 102 may include a transducer which is operative to provide asignal responsive to the pressure of the gases in the tube. Such asignal may be representative of the depth of the fluid 46 in thereservoir. Examples of fluid level sensing devices are shown in U.S.Pat. No. 6,595,051 of Jul. 22, 2003 and U.S. Pat. No. 6,443,005 of Sep.3, 2002 which are both incorporated by reference herein. Alternativeexemplary embodiments of the present invention may use other fluid levelsensing devices such as floats or other sensors mounted in the reservoirat known positions for example.

In the described exemplary embodiment, the control panel 102 isoperative to monitor conditions associated with the wastewater systemsuch as the depth levels of the fluid 46. Responsive to the depth level,the control panel is operative to turn one or more pumps 40 on and offto maintain the level of the fluid below a threshold.

Although the described exemplary embodiment is operative to cause pumpsto move water out of the tank 20, it is to be understood that inalternative exemplary embodiments, the system may include valves, orother fluid control devices which are operative to control either orboth of the input and output of fluids into the tank.

Although exemplary embodiments are described herein as being responsiveto conditional signals representative of a depth level of a fluid, infurther exemplary embodiments the system may monitor and be responsiveto other condition signals. Such other condition signals may, forexample, include the health of various components of the system such aspumps, valves, and other devices. The control panel may be configured todetermine that an alarm should be activated responsive to one or more ofthe conditions signals corresponding to one or more alarm levelsspecified using the control panel.

FIG. 2 shows an example of one exemplary embodiment of a control panel102 for use with exemplary embodiments of fluid level sensing andcontrol systems. Here the control panel 102 includes a housing 104. Thehousing may be comprised of different materials such as stainless steel,plastic, or other materials, depending on the intended environment forwhich the control panel will be exposed. In this described exemplaryembodiment the housing is comprised of a nonconductive material such apolycarbonate. Also, in this described exemplary embodiment, the housingincludes a hinged door 110. The door includes a gasket 112 which isoperative to provide a water resistant seal when the door is latchedinto a closed position with the body 114 of the housing. Although, inthis described exemplary embodiment the door includes the gasket 112, itis to be understood that in alternative exemplary embodiments the gasketmay be mounted to the body of the housing and/or other sealing devicesand features may be used to enable the housing to prevent or at leastminimize the opportunity for fluids such as water or corrosive fluidsand gases from entering the housing. In exemplary embodiments, thefeatures of the control panel described herein enable the housing tomeet the requirements of the National Electrical ManufacturersAssociation (NEMA) 4X standard for water and other fluid penetrations.

In an exemplary embodiment, the control panel 102 may include twomounting panels in operative connection with the housing. As shown inFIG. 2, a first one of the mounting panels includes a sub-door 120 thatis in hinged connection with the housing. In FIG. 2, the sub-door isshown in a closed position. As shown in FIG. 3, the sub-door 120 isoperative to pivot to an open position which provides a user with accessto a second one of the mounting panels. In this described exemplaryembodiment, the second one of the mounting panels corresponds to a backpanel 122 mounted adjacent the inner back wall of the housing. The backpanel is adapted to hold components which may have potentially hazardousunshielded electrical connections. Such components, for example, mayinclude contact relays 130 for use in powering one or more pumps. Suchcomponents may also include start capacitors 132 and start relays foruse with activating start windings in the motors of single phase pumps.Such components may also include circuit breakers 124 coupled todifferent electrical portions of the control panel.

As shown in FIG. 2, when the sub-door is in the closed position, thesub-door has a sufficient size, shape and surface area to cover theunshielded portions of components mounted to the back panel and preventa user's hand and fingers from touching unshielded portions ofcomponents mounted to the back panel. As a result, the sub-door providesadditional safety for a use against accidental electrical shock whenconfiguring the control panel.

The sub-door may be comprised of plastic, stainless steel, or any othermaterials which are operative to support components of the controlpanel. In this described exemplary embodiment the sub-door is comprisedof a nonconductive material such as a polycarbonate which is injectionmolded to include features for mounting different types of components.

As shown in FIG. 2, the sub-door includes an outer face 140 which isadapted to receive mounted thereto a plurality of input and outputdevices 146, 148. The input and output devices of the sub-door areviewable and/or accessible to a user when the sub-door is in the closedposition. Such input and output devices may include for exampleindicator lights such as LEDs, push buttons, control dials, digitaldisplays, and other user interface features which enable a user togather information and/or control the operation of a wastewater or otherfluid system.

As shown in FIG. 3, the sub-door further includes an inner side 142. Theinner side is accessible to a user when the sub-door is in the openposition. The inner side 142 may be adapted to receive mounted theretoone or more circuit boards 150, 152 or other components which areconfigured and/or programmed to output information using the outputdevices and receive information using the input devices of the sub-door.FIG. 4 shows an example of the outer side 140 of the sub-door withoutcomponents mounted thereto. FIG. 5 shows an example of the inner side142 of the sub-door without components mounted thereto.

In an exemplary embodiment, the sub-door includes a plurality ofapertures 160, 162, 164, 168. When the previously described circuitboards are mounted to the inner side of the sub-door, the apertures areoperative to receive therethrough or at least make accessible orviewable input and output devices mounted to the circuit boards.

As shown in FIG. 3, the sub-door may include a first or main circuitboard 150. The main circuit board may include a computer processor andassociated circuitry which is operatively configured and programmed toperform a default set of functions. Such functions may includeactivating the relays which start, run and stop one or more pumps forexample. Such functions may also include determining the depth level ofthe fluid. Such functions may also include enabling a user to provide aplurality of different depth levels or other threshold information whichis used by the main circuit board to determine when to start and stoppumps and when to activate one or more visible, audible, or other alarmsignals. In an exemplary embodiment, pumps and alarms may be operationalin the control panel without the addition of further circuit boards tothe sub-door.

However, the exemplary embodiment of the sub-door is further adapted toreceive additional optional circuit boards 152. Such optional circuitboards may provide additional user interface features with additionalinput and output devices that are accessible to a user from the outerside of the sub-door.

In an exemplary embodiment, an optional circuit board may include adigital display device that is viewable through an aperture 162 (FIG. 5)of the sub-door. The sub-door may include further apertures 168 whichenable a user to access additional input devices such as buttons locatedon the optional circuit board.

The optional circuit board may be placed in operative electricalcommunication with the main circuit board with one or more communicationlines 170 (FIG. 3). In the exemplary embodiment, the processor of themain circuit board is operatively programmed to provide information tothe processor of the optional circuit board. Such information mayinclude the depth level of the fluid, the status of pumps and alarms,and/or any other information which is available to the main circuitboard.

The processor of the main circuit board may further be operativelyprogrammed to be responsive to commands from the processor of theoptional circuit board to alter its default programming. For example,the processor of the optional circuit board may be operative to send theprocessor of the main circuit board commands to start and stop variouspumps and alarms. The processor of the main circuit board may beoperative to control the operation of the pumps and alarms responsive tothe commands from the processor of the optional circuit board.

In addition, the processor on the main circuit board may also be adaptedto accept updates to code, additional code and/or complete upgrades toits programming code which are received from the processor of theoptional circuit board. For example, a user may install a new optionalcircuit board to a pre-existing control panel. Such an optional circuitboard may include a memory which is used to store programming code suchas firmware instructions intended for use with upgrading the main board.When the optional circuit board is connected to the main circuit board,both boards may be adapted to undergo a handshaking protocol whichenables the optional circuit board to upgrade the processor on the mainboard with the new/additional code. Such a protocol may include thecircuit boards swapping version, security information and/or otherinformation which can be used by the boards to verify that the new codeshould be permitted to be installed on the main board. Examples ofcomponents which may be used to provide upgrade functionality of themain circuit board from an optional circuit board include the flashPICmicro® microcontroller devices by MicroChip®.

In further exemplary embodiments, the sub-door may be operative toreceive additional optional circuit boards. Such additional optionalcircuit boards may be mounted in stacked relation with the previouslymounted optional circuit boards. In an exemplary embodiment, when acontrol panel does not have an optional circuit board mounted therein,the sub-door may include a face plate which snaps onto the sub-door andcovers the apertures 162, 168 on the sub-door.

Exemplary embodiments of the optional circuit boards may provide adigital display of the depth level, alarm information, or any otherinformation available to the main board and optional circuit boards.Further the optional circuit boards may provide other additionalfunctions to the control panel. Such functions may include an elapsedpump operating time meter, pump off/on cycle counter, liquid leveldisplay, time dosing applications, measurement logs, alarm conditionannunciations, telemetry and other communications with remote devices.

Referring back to FIG. 2, exemplary embodiments of the control panel mayinclude a housing 104 which includes T-shaped rails or brackets 200extending inwardly adjacent inner corners of the housing body. TheT-shaped rails may be used to mount components in the housing. However,it is to be understood that in other exemplary embodiments, other typesof housings and mounting brackets or rails may be used.

To enable the sub-door to be in hinged connection with the housing, theexemplary embodiment may include hinge brackets 202 which are adapted tomount to the T-shaped rails of the housing. As shown in FIGS. 6 and 7,the hinge brackets 202 include at least one cylindrical projection 204.When two of the hinge brackets are mounted to the T-shaped rails of thehousing (FIGS. 2 and 3) the projections are coaxially aligned andprovide a mounting point for the sub-door. As shown in FIG. 5, thesub-door includes two concave flanges or grooves 208 on one side of thesub-door which are adapted to snap onto the projections 204 of the hingebrackets 202 (FIG. 3). The exemplary embodiment of the sub-door isoperative to pivot on the projections 204 of the hinge brackets betweenthe previously described closed position (FIG. 2) and open position(FIG. 3). When mounted to the projections 204, the concave flanges 208may be operative to extend more than 180 degrees around the projectionsto mechanically hold the sub-door to the housing.

In exemplary embodiments, the sub-door is operative to snap onto and offof the projections of the hinge brackets without the use of tools toenable the control panel to be easily manufactured and to enable anexisting sub-door on a control panel to be easily replaced with afurther sub-door. Exemplary embodiments of the hinge brackets mayinclude two projections oriented at 90 degrees. Such brackets may bemounted on either an upper or lower T-shaped rail and be able to provideat least one projection which is orientated vertically 207. Exemplaryembodiments of the sub-door may further include cut out portions 203 inthe location of the non-used horizontal projections 205 for each hingebracket when the sub-door is in the closed position.

As shown in FIG. 3, exemplary embodiments may further include a threadedmounting bracket 210 which is also adapted to mount to a T-shaped railof the housing. The threaded mounting bracket may include a threadedaperture which is operative to receive a threaded locking bolt. As shownin FIG. 2, the threaded locking bolt 212 may extend through the sub-door120, in aligned relation with the threaded bracket. The locking bolt 212may then be rotated clockwise into the threaded bracket to lock thesub-door in the closed position. The locking bolt may then be rotatedcounter-clockwise out of the threaded bracket to enable the sub-door topivot to the opened position.

FIG. 8 shows an exemplary embodiment of a back panel 122 withoutcomponents mounted thereto. The back panel may be adapted to mountadjacent the back inner wall of the housing. The back panel may becomprised of plastics, stainless steels or any other material which isoperative to support components of the control panel. In this describedexemplary embodiment, the back panel is comprised of a nonconductivematerial such as a polycarbonate which is injection molded to includefeatures for mounting different types of components.

An exemplary embodiment of the back panel may include a raised platform230 which is adapted to receive one or more circuit breakers mountedthereto. The raised platform may have a height relative the back wall ofthe housing which places the switches of the circuit breakers adjacentor through an aperture 160 (FIG. 5) of the sub-door.

The back panel may also include raised bosses 232 and/or other molded inbrackets for mounting one or more relays for use with controlling theoperation of pumps. The back panel may also include a raised bracket 234with circular openings 236 therethrough for mounting one or more startcapacitors to the back panel. The back panel may further include angledor curved ramps 238 with slots 240 therethrough for receiving tie downsor other straps for rigidly holding the capacitors to the back panel.

The raised bracket 234 may further include an upper surface 237 orientedat an acute angle with respect to the back inside surface of the housingand/or back panel 231. As shown in FIG. 3, a terminal block 139 may bemounted to the upper surface 237 of the raised bracket 324 eitherdirectly or through use of a rail 135. The terminal block may be used toorganize and/or label the various electrical connections betweencomponents of the control panel (e.g. circuit breakers, relays, maincircuit board, and alarms) and other portions of the waste water system(e.g. pumps, floats, incoming power). Orientating the upper surface 237at a non-parallel angle with respect to the back inside surface of thehousing, provides the end user with a more convenient angle to connectand disconnect wires to the terminal block using a screw driver or othertool.

FIG. 9 shows an example of one of a plurality of differentconfigurations for a user interface area 300 on the outer side of thesub-door. Here the user interface area 300 provides access to aplurality of input and output devices 146 which are included on the mainboard positioned on the inner side of the sub-door. In this exemplaryembodiment of the control panel, the user interface may include aplurality of fluid depth level selection devices 302. Here the fluiddepth level selection devices correspond to rotatable dials which bychanging the angular position of the dials, enable a user to select adepth level associated with functions of the control panel.

For example a first one of the selection devices 310 enables a user toselect the depth level at which the processor of the main circuit boardcauses pumps associated with the system to be turned off. A secondselection device 312 enables a user to select the depth level at whichthe processor of the main circuit board causes a first pump to be turnedon to move fluid out of a tank. A third selection device 314 enables auser to select the depth level at which the processor of the maincircuit board will cause a second or lag pump to be turned on to movefluid out of the tank. A fourth selection device 316 enables a user toselect the depth level at which the processor of the main circuit boardwill cause a high fluid level alarm to be output by the control panel.

The exemplary embodiment of the user interface area 300 may furtherinclude a plurality of output devices 320 which indicate the currentoperating status of the control panel. Such output devices may includefor example LEDs which indicate which pumps are currently operating andwhether or not an alarm signal is being outputted by the control panel.

The exemplary embodiment of the user interface area 300 may furtherinclude command buttons 322 which cause the main board to performdifferent functions. For example, the command buttons may include pushbuttons 330 and 332 associated with each pump. The processor of the maincircuit board may be responsive to these buttons being engaged by a userto immediately turn on the pump associated with the button. In anexemplary embodiment, the pumps may continue to run until either thebutton is engaged again or the depth level of the fluid falls to thelevel selected by the pump off selection device 310.

In an exemplary embodiment, when the depth level of the fluid in thetank is at or lower than the depth level selected by the pump offselection device 310, the main board may be operative to change thebehavior of the push buttons 330, 332 to that of momentary contactbuttons in which the pump only operates while the button continues to bepressed by a user. As a result when the user removes his finger from thebutton, the pumps will automatically stop to prevent the pump fromrunning dry.

In this described exemplary embodiment, the user interface area 300 mayfurther include a push button 334 associated with the control panelalarms. Pressing the alarm push button 334 when an audible and/or visualalarm is not on, will cause the processor of the main circuit board toturn on the control panel alarms for use in testing the system. When thealarms are on, the alarm push button 334 is operative to silence one ormore of the alarms so that the system can be attended to by a userwithout having to continually listen to an audible alarm for example.

The described exemplary embodiment of the user interface area 300 isonly one example configuration for a user interface associated withexemplary embodiments of the control panel. It is to be understood thatin alternative exemplary embodiments, components of the control panelmay require different user interface input and output devices. Forexample, some exemplary embodiments of an associated wastewater systemmay only have one pump. As a result the user interface area and the maincircuit board may only be configured to operate one pump. Further someexemplary embodiments of an associated wastewater system may have floatsrather than a pressure bell. As a result, fluid depth level selectiondevices 302 may not be present on the corresponding user interface areaand main circuit board of the control panel for such systems.

In exemplary embodiments of the system which include a digital displaysuch as an alphanumeric LED panel 308, the system may be operative tocause the LED panel to display numerical values associated with thecurrent position selector device being manipulated by a user. Forexample, if a user rotates one of the dials of the selection devices302, the main processor associated with the system may be operative tocause the LED panel 308 to display a number representative of the depthlevel in inches or other units of length that the dial is currentlyassociated with. Such an LED panel may provide a more accurate displayof the position of the dial than can be determined from the relativelysmall hash marks and numerical labels 303 positioned around the dial.

FIG. 2, shows an example of a digital display 148 which is integratedinto an optional circuit board. In this described exemplary embodiment,the main board is operative to communicate the numerical valuesassociated with a selection device on the main board to the optionalcircuit board. The optional circuit board may then be operative to causeits digital display to output the numerical value provided by the maincircuit board. In alternative exemplary embodiments, the main circuitboard may include a digital display which is operative to output anumerical value indicative of the position of the selection devices 302of the main board.

In exemplary embodiments which do not have a digital display either onan optional circuit board or on the main board, the main board may beoperative to provide an electrical circuit for each selection devicewhich is adapted to output a voltage potential which has a value involts which corresponds to the value represented by the position of thedial of the selection device. For example as shown in FIG. 9, the dials304 of each selection device may include a conductive surface contactpoint 305. A user may connect a hand held voltmeter to the conductiveservice 305 of the dial 304 and to a grounding conductive surface 306located on the main board. The main board may include a circuitassociated with the conductive surface 305 on the dial which isoperative to cause the voltmeter to display a value in volts whichrepresents the depth level in units or fractions of units of lengthassociated with the current position of the selection device.

In an exemplary embodiment, a voltage measurement displayed by thevoltmeter connected in this manner may be multiplied by ten to determinethe corresponding depth in inches or other units of length of the fluid.For example, when the dial is turned to a position which represents adepth level of 15.14 inches, the voltage provided by the circuitassociated with the dial and which is displayed by the voltmeter wouldbe 1.514 volts. A user may then multiply this amount in volts by 10 todetermine the corresponding value in inches at which the selectiondevice is currently set.

FIG. 14 shows an exemplary embodiment of a portion of the circuit 600 onthe main board which includes the selection devices 310–316. Here theselection devices include potentiometers which are in operativeconnection with a microprocessor 602 of the main board. In the exemplaryembodiment, the processor is operative to control the pumps and alarmsresponsive to the positions of the selection devices as describedherein. Each of the potentiometers may include a metal tab conductivesurface 305 adjacent the portion of the dial which turns thepotentiometer. Each metal tab shares a common electrical connection withthe wiper output of the corresponding potentiometer and provides alocation to measure the voltage associated with the position of thepotentiometer using a voltmeter. The circuit shown in FIG. 14 alsoincludes a ground 306 to which the voltmeter may also be connected. Thisgrounding conductive surface may correspond to a grounded screw 306(FIG. 9) or other metal surface which is accessible to the voltmeterwhen the sub-door is closed.

In exemplary embodiments, the control panel may have an alarm silenceinput device that can be activated by a user when the housing door isclosed. FIG. 10 shows a schematic view of an exemplary embodiment forsuch an alarm silence input device 400. Here the device includes a touchpad such as a conductive metal plate 406. As shown in FIG. 11, the plateis mounted to an inside wall 402 of the housing 104. In this describedexemplary embodiment, the housing is comprised of a nonconductivematerial which is operative to experience a change in capacitance as aresult of a user placing his fingers, hand or other body part adjacentthe touch pad on the outside of the housing. FIG. 12 shows a view of theoutside surface 404 of the housing wall which corresponds to theposition of the plate. To enable a user to locate the correct locationon the housing which is adjacent the plate, the outside surface 404 ofthe housing may include a label, sticker, painted graphic, molded-insymbols, or other indicia which indicates to a user where the housingmay be touched by the user to silence the alarm.

Referring back to FIG. 10, the control panel may further include a touchsensor chip 410 which is operatively programmed to provide a signal inresponse to the capacitance of the plate changing to a level whichindicates the presence of a user's hand or fingers. Examples of suchtouch sensor chips include the QT110 Family of QTouch Sensors fromQuantum Research Group Ltd.

The signal from the touch sensor chip 410 may be communicated to theprocessor 408 of the main circuit board of the system. In the exemplaryembodiment, the processor 408 of the main circuit board may beprogrammed to cause one or more alarm signaling devices 412 to besilenced in response to the touch sensor chip providing a signalrepresentative of the detection of a user's hand.

In an exemplary embodiment, the touch sensor pad may correspond to a 3inch by 3 inch aluminum plate. In other exemplary embodiments the padmay correspond to a copper plane of a circuit board. In alternativeexemplary embodiments other sizes, shapes and configurations of the padmay be used depending on the desired sensitivity for the device.

In alternative exemplary embodiments, the processor of the main circuitboard may be programmed to test the alarm signaling devices 412responsive to the detection of a user's hand adjacent the touch sensorpad. For example, when the alarm signaling device is in an inactivestate and/or a condition signal does not correspond to an alarm level,the processor may activate the alarm signaling devices for apredetermined amount of time responsive to the touch sensor pad sensinga user's hand. The predetermined amount of time may be 10 seconds forexample or some other amount of time which enables a user to verify thatthe internal and/or external alarm signaling devices connected to thesystem are working properly.

As discussed previously, exemplary embodiments of the control panel maybe configured to start and stop single phase AC motor pumps. The motorsof such pumps include start windings which the processor of the maincircuit board is operative to temporarily cause to be powered forpurposes of accelerating the motor of the pump. FIG. 13 shows aschematic view of some of the components involved with the starting of amotor 500 of a pump. Here the circuit may include a start relay 502which is responsive to the processor 408 of the main board to open andclose the circuit which provides current to activate the start windings504 of the motor.

In the exemplary embodiment, start capacitors operate in parallel withthe start windings 504. As the motor accelerates the voltage applied tothe start capacitors increases. To prevent the start capacitors frombeing damaged, the processor 408 is operative to deactivate the startwindings before the motor reaches full speed.

In this described exemplary embodiment, the control panel may include anoverload device 506 which is operative to measure the current in the ACcircuit which powers the run windings of the pump motor. The processor408 may monitor the measured level of current by the overload device.When the processor determines that the measured level of current dropsto a predetermined level, the processor may be operatively programmed tocause the start relay 502 to deactivate the start windings. In theexemplary embodiment, the predetermined level of current which triggersthe start windings to be deactivated may correspond to a current levelat which the motor reaches 75% of full speed for example. However, it isto be understood that in alternative exemplary embodiments, otherpredetermined levels of current and/or speed may be chosen for when todeactivate the start windings.

In the exemplary embodiment, the processor 408 may further be operativeto determine the amount of time that has elapsed since the processorcaused the contact relays to provide power to both the start windings504 and the run windings 510 of the motor. When the amount of time thathas elapsed has reached a predetermined amount of time, the processormay be operative to deactivate the start windings. In an exemplaryembodiment the predetermined amount of time may correspond to about 1–3seconds, for example.

In the exemplary embodiment, the processor may monitor the overloaddevice or another circuit which is operative to measure the sinusoidalchanges of the current in the AC circuit powering the run windings ofthe motor of the pump. The processor may be operative to time the pointwhen the contact relay closes the circuit for the run windings to aboutcorrespond to the cross-over point or zero power point of the sinusoidalchange in voltage in the AC circuit. The processor may be operative totime the point when the contact relay opens the circuit for the runwindings to about correspond to the cross-over point or zero power pointof the sinusoidal change in current in the AC circuit. For example, theprocessor may cause the contact relay to power and/or remove power fromthe run windings responsive to the current or voltage of the AC circuitbeing within a predetermined amount of time before or after thecross-over point for the AC circuit. The cross-over point corresponds towhen the alternating current switches directions. In an exemplaryembodiment the predetermined amount of time may for example be about 1millisecond. In an exemplary embodiment, operating the contact relayswithin a predetermined amount of time of the cross-over point for the ACcircuit may reduce the amount of wear on the contact relays and mayenable the use of relatively smaller and relatively less expensiverelays to control power to the run windings of the motor.

In addition to the described exemplary embodiments of the control panel,it is to be understood that other alternative exemplary embodiments mayhave other configurations with different sets of features andcomponents. For example, control panels may be constructed with alimited subset of some of the features described herein. Further, otheralternative exemplary embodiments may have other features useful formonitoring and controlling components in a wastewater system.

Thus the fluid level sensing and control system achieves one or more ofthe above stated objectives, eliminates difficulties encountered in theuse of prior devices and systems, solves problems and attains thedesirable results described herein.

In the foregoing description certain terms have been used for brevity,clarity and understanding, however no unnecessary limitations are to beimplied therefrom because such terms are used for descriptive purposesand are intended to be broadly construed. Moreover, the descriptions andillustrations herein are by way of examples and the invention is notlimited to the exact details shown and described.

In the following claims any feature described as a means for performinga function shall be construed as encompassing any means known to thoseskilled in the art to be capable of performing the recited function, andshall not be limited to the features and structures shown herein or mereequivalents thereof. The description of the exemplary embodimentincluded in the Abstract included herewith shall not be deemed to limitthe invention to features described therein.

Having described the features, discoveries and principles of theinvention, the manner in which it is constructed and operated, and theadvantages and useful results attained; the new and useful structures,devices, elements, arrangements, parts, combinations, systems,equipment, operations, methods and relationships are set forth in theappended claims.

1. A control panel apparatus for a wastewater system comprising: ahousing; at least one processor mounted within the housing, wherein theat least one processor is adapted to receive at least one conditionsignal representative of a condition associated with a reservoircomprising a fluid; at least one alarm output device in operativeconnection with the at least one processor, wherein the at least oneprocessor is operative responsive to the at least one condition signalto cause the at least one alarm output device to output an alarm signal;and at least one contact relay mounted within the housing, wherein theat least one contact relay is operative to open and close at least oneAC circuit which is operative to power run windings of at least onemotor of at least one pump, wherein the at least one pump is operativeto change a depth level of the fluid level in the reservoir responsiveto the at least one condition signal, wherein the at least one processoris operative to cause the at least one contact relay to at least one ofopen and close the at least one AC circuit responsive to the at leastone condition signal and responsive to at least one of current andvoltage of the at least one AC circuit being within a predeterminedamount of time of a cross-over point.
 2. The apparatus according toclaim 1, further comprising: at least one start relay mounted within thehousing and adapted to open and close at least one further circuit whichpowers start windings of the at least one motor of the at least onepump; wherein the at least one processor is operative to start the atleast one motor of the at least one pump responsive to the at least onecondition signal by causing the at least one contact relay to close theat least one AC circuit and by causing the at least one start relay toclose the at least one further circuit; wherein responsive to a currentassociated with the run windings corresponding to a predetermined level,the at least one processor is operative to cause the at least one startrelay to open the at least one further circuit.
 3. The apparatusaccording to claim 1, wherein the housing complies with at least theNational Electrical Manufacturers Association (NEMA) 4X standard forfluid penetrations.
 4. The apparatus according to claim 1, furthercomprising at least one input device in operative connection with the atleast one processor, wherein the at least one input device is operativeto specify at least one alarm level, wherein the at least one processoris operative to cause the at least one alarm to output the alarm signalresponsive to the at least one alarm level and the at least onecondition signal.
 5. The apparatus according to claim 4, wherein thehousing includes an opening and a door that is operative to close theopening, wherein the housing further includes a sub-door in hingedconnection with an inside portion of the housing, wherein the at leastone processor is mounted to the sub-door.
 6. The apparatus according toclaim 1, further comprising: the reservoir; at least one fluid levelsensing device positioned within the reservoir and in operativeconnection with the at least one processor, wherein the at least onecondition signal is produced responsive to the at least one fluid levelsensor device and is representative of the depth level of the fluid inthe reservoir.
 7. The apparatus according to claim 6, wherein the atleast one fluid level sensing device comprises a pressure bellpositioned in the reservoir.
 8. The apparatus according to claim 6,wherein the at least one fluid level sensing device comprises at leastone float device positioned in the reservoir.
 9. The apparatus accordingto claim 6, wherein the fluid includes wastewater.
 10. A methodcomprising: a) monitoring at least one condition signal with at leastone processor of a control panel apparatus, which at least one conditionsignal corresponds to a depth level of a fluid in a reservoir, whereinthe apparatus includes at least one contact relay operative to open andclose at least one AC circuit operative to power run windings of atleast one motor of at least one pump; b) determining with the at leastone processor that the at least one condition signal corresponds to atleast one predetermined condition associated with the fluid in thereservoir; c) responsive to (b) controlling operation of the at leastone pump, including: i) determining that at least one of current andvoltage associated with the at least one AC circuit is within apredetermined amount of time of a cross-over point; ii) causing with theat least one processor the at least one contact relay to at least one ofopen and close the at least one AC circuit responsive to (i).
 11. Themethod according to claim 10, wherein the apparatus includes at leastone start relay, wherein the start relay is operative to open and closeat least one further circuit which powers start windings of the at leastone motor of the at least one pump, wherein (c) includes causing withthe at least one processor, the at least one pump to change the depthlevel of the fluid level in the reservoir, wherein (c)(ii) includescausing with the at least one processor the at least one contact relayto close the at least one AC circuit, wherein (c) further includes: iii)causing with the at least one processor the at least one start relay toclose the at least one further circuit.
 12. The method according toclaim 11, wherein (c) further includes: iv) determining with the atleast one processor that the current associated with the run windingscorresponds to a predetermined level; v) responsive to (iv) causing withthe at least one processor, the at least one start relay to open the atleast one further circuit.
 13. The method according to claim 12, whereinin (iv) the predetermined level of current corresponds to the at leastone motor of the at least one pump operating at least at 75% of fullspeed.
 14. The method according to claim 11, wherein (c) furtherincludes: iv) determining with the at least one processor that an amountof time has elapsed since (iii) which corresponds to a predeterminedamount of time; v) responsive to (iv) causing with the at least oneprocessor, the at least one start relay to open the at least one furthercircuit.
 15. The method according to claim 10, further comprising: d)responsive to (b) causing with the at least one processor, at least onealarm output device in operative connection with the apparatus to outputan alarm signal.
 16. The method according to claim 10, wherein theapparatus comprises a housing which includes the at least one contactrelay therein, wherein the housing includes an opening and a door thatis operative to close the opening, wherein the housing further includesa sub-door in hinged connection with an inside portion of the housing,wherein the apparatus comprises a main circuit board in operativeconnection with the sub-door, wherein the main circuit board includesthe at least one processor, wherein while the apparatus is in operativeconnection with at least one fluid level sensing device positionedwithin the reservoir further comprising: d) installing an optionalcircuit board in operative connection with the sub-door, wherein theoptional circuit board includes a second at least one processor, whereinthe optional circuit board includes a code upgrade; e) upgrading the atleast one processor on the main circuit board responsive to the codeupgrade accessed from the optional circuit board; f) communicating dataassociated with the at least one condition signal from the at least oneprocessor on the main circuit board to the second at least one processoron the optional circuit board.
 17. The method according to claim 10,wherein the apparatus comprises a housing which includes the at leastone contact relay therein, wherein the housing includes an opening and adoor that is operative to close the opening, wherein the housing furtherincludes a first sub-door in hinged connection with an inside portion ofthe housing, wherein the apparatus comprises a main circuit board inoperative connection with the first sub-door, wherein the main circuitboard includes the at least one processor, wherein while the apparatusis in operative connection with at least one fluid level sensing devicepositioned within the reservoir further comprising: d) replacing thefirst sub-door with a second sub-door, wherein the second-sub doorincludes a main circuit board and an optional circuit board, wherein theoptional circuit board is operative to at least one of: displayinformation representative of at least one condition signal through adigital display device of the optional circuit board; displayinformation representative of at least one alarm level through a digitaldisplay device of the optional circuit board; store pump operating datain at least one data store of the optional circuit board; and store datain a data store of the optional circuit board, which data isrepresentative of the depth level of the fluid in the reservoir overtime.
 18. The method according to claim 17, wherein the housing includesat least two parallel rails adjacent opposed corners of the housing,wherein each of the two parallel rails includes mounted thereto a hingebracket, wherein each hinge bracket includes at least one projection,wherein the projections of the at least two hinge brackets are coaxiallyaligned, wherein in (g) the first and second sub-doors include a concaveportion which is adapted to mount to the projections of the hingebrackets.
 19. A method comprising: a) monitoring at least one conditionsignal with at least one processor of a control panel apparatus, whereinthe at least one condition signal is generated by a fluid level sensingdevice positioned within a reservoir, wherein the at least one conditionsignal corresponds to a depth level of a fluid in the reservoir, whereinthe apparatus includes a housing, wherein the housing includes thereinat least one relay operative to open and close at least one AC circuitoperative to power run windings of at least one motor of at least onepump, wherein the housing includes an opening and a door that isoperative to close the opening, wherein the housing further includes afirst sub-door in hinged connection with an inside portion of thehousing, wherein the first sub-door includes the at least one processorthereon; b) determining with the at least one processor that the atleast one condition signal corresponds to at least one predeterminedcondition associated with the fluid in the reservoir; c) responsive to(b) controlling operation of the at least one pump with the at least oneprocessor to change a depth level of the fluid in the reservoir,including causing with the at least one processor the at least one relayto at least one of open and close the at least one AC circuit; and d)replacing the first sub-door with a second sub-door, wherein thesecond-sub door includes at least one second processor operative tocarry out (a), (b) and (c), wherein the second sub-door includes anoptional circuit, wherein the optional circuit is operative to at leastone of: i) display information representative of at least one conditionsignal through a digital display device in operative connection with thesecond sub-door; ii) display information representative of at least onealarm level through a digital display device in operative connectionwith the second sub-door; iii) store pump operating data in a memorydevice in operative connection with the second sub-door; and iv) storedata in a memory device in operative connection with the secondsub-door, wherein the data is representative of the depth level of thefluid in the reservoir over time.
 20. The method according to claim 19,wherein (c) includes determining that at least one of current andvoltage associated with the at least one AC circuit is within apredetermined amount of time of a cross-over point, wherein (c) includescausing with the at least one processor the at least one relay to atleast one of open and close the at least one AC circuit responsive todetermining that the at least one of current and voltage associated withthe at least one AC circuit is within a predetermined amount of time ofa cross-over point.